U.S. patent application number 17/397877 was filed with the patent office on 2022-02-17 for metal-oxygen primary reserve batteries for munitions and the like applications.
This patent application is currently assigned to Omnitek Partners LLC. The applicant listed for this patent is Omnitek Partners LLC. Invention is credited to Javier Alvare, Jahangir S. Rastegar.
Application Number | 20220052398 17/397877 |
Document ID | / |
Family ID | |
Filed Date | 2022-02-17 |
United States Patent
Application |
20220052398 |
Kind Code |
A1 |
Rastegar; Jahangir S. ; et
al. |
February 17, 2022 |
Metal-Oxygen Primary Reserve Batteries for Munitions and the Like
Applications
Abstract
A metal-gas battery including: a battery core, gas container and
a movable member. The battery core including a metal anode; a
non-aqueous electrolyte; a porous cathode; and terminals for
providing electrical power from the battery core. The gas container
being configured to hold a pressurized gas. The movable member
being configured to be movable from a non-activated position in
which the pressurized gas in the container is sealed from entering
the porous cathode and an activated position in which the
pressurized gas flows into the porous cathode to activate the
battery core.
Inventors: |
Rastegar; Jahangir S.;
(Stony Brook, NY) ; Alvare; Javier; (Sandy,
UT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Omnitek Partners LLC |
Ronkonkoma |
NY |
US |
|
|
Assignee: |
Omnitek Partners LLC
Ronkonkoma
NY
|
Appl. No.: |
17/397877 |
Filed: |
August 9, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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63064325 |
Aug 11, 2020 |
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International
Class: |
H01M 12/06 20060101
H01M012/06; H01M 4/38 20060101 H01M004/38; H01M 4/583 20060101
H01M004/583 |
Claims
1. A metal-gas battery comprising: a battery core comprising: a
metal anode; a non-aqueous electrolyte; a porous cathode; and
terminals for providing electrical power from the battery core; a
container configured to hold a pressurized gas; and a member
configured to be movable from a non-activated position in which the
pressurized gas in the container is sealed from entering the porous
cathode and an activated position in which the pressurized gas
flows into the porous cathode to activate the battery core.
2. The metal-gas battery of claim 1, wherein the battery core
comprises a housing for hermetically sealing the metal anode,
non-aqueous electrolyte and porous cathode therein.
3. The metal-gas battery of claim 2, wherein: the housing having a
hole providing fluid communication between the housing and the
container; a diaphragm sealingly closing the hole; and the member
has a portion configured to rupture the diaphragm when moved to the
activated position; wherein the member is biased in the
non-activated position.
4. The metal-gas battery of claim 3, wherein the member is
configured to move to the activated position when the member
experiences a predetermined acceleration profile.
5. The metal-gas battery of claim 3, wherein the member is
configured to move to the activated position when the member is
moved to the activated position by an applied force.
6. The metal-gas battery of claim 5, wherein: the member includes
an extending portion; and a bellows sealingly covers the extended
portion, the bellows at least partially biasing the member in the
non-activated position.
7. The metal-gas battery of claim 1, further comprising an
activation device configured to move the member to the activated
position, the activation device providing a force to move the
member to the activated position.
8. The metal-gas battery of claim 7, further comprising an energy
storage device configured to receive at least a partial amount of
energy generated by the battery core after the member is moved to
the activated state, the energy storage device at least partially
providing the received energy to operate the actuation device to
selectively move the member between the non-actuated and actuated
positions.
9. The metal-gas battery of claim 8, wherein the energy storage
device is under the control of a controller.
10. The metal-gas battery of claim 2, wherein: the housing having a
hole providing fluid communication between the housing and the
container; the member has a first portion configured to seal the
hole when in the non-activated position, the member having a second
portion connected to the first portion through the hole; a spring
for biasing the second portion away from the hole such that the
first portion sealingly engages the hole when the member is in the
non-activated position.
11. The metal-gas battery of claim 10, wherein at least the second
portion and spring are configured to move the member to the
activated position when the member experiences a predetermined
acceleration profile.
12. The metal-gas battery of claim 11, further comprising an other
member configured to be movable when the member moves into the
activated position to prevent the member from moving back into the
non-activated position.
13. The metal-gas battery of claim 1, further comprising a spring
for biasing the member in the non-activated position.
14. The metal-gas battery of claim 1, wherein the member is
provided at least partially in the container.
15. The metal-gas battery of claim 1, wherein the member is
provided at least partially in the porous cathode.
16. The metal-gas battery of claim 1, wherein the member moves in
translation from the non-activated position to the activated
position.
17. The metal-gas battery of claim 1, wherein the member moves in
rotation from the non-activated position to the activated
position.
18. The metal-gas battery of claim 1, further comprising an
obstruction member for obstructing the movement of the member from
the non-activated position to the activated position, wherein the
obstructing member is configured to be manually removed to allow
movement of the member from the non-activated position to the
activated position.
19. The metal-gas battery of claim 1, further comprising an other
member configured to prevent movement of the member to the
non-activated position after achieving the activated position.
20. The metal gas battery of claim 1, wherein the member is
configured to selectively move from the activated position to the
non-activated position.
21. The metal-gas battery of claim 1, wherein the metal anode is
Lithium.
22. The metal-gas battery of claim 1, wherein the pressurized gas
is Oxygen or a gas containing Oxygen.
23. The metal-gas battery of claim 22, wherein the porous cathode
is a porous Carbon-based cathode.
Description
CROSS-REFERNCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 63/064,325, filed on Aug. 11, 2020, the entire
contents of which is incorporated herein by reference.
BACKGROUND
Field
[0002] The present invention relates generally to reserve power
sources for munitions and other similar applications; and more
particularly to Lithium-oxygen reserve batteries and methods of
their activation for use in gun-fired munitions, sub-munitions,
mortars, and the like. The Lithium-oxygen batteries may be
activated and deactivated as required to satisfy the system power
requirement and to maximize the power source run time.
Prior Art
[0003] Reserve batteries of the electrochemical type are well known
in the art for a variety of uses where storage time before use is
extremely long. Reserve batteries are in use in applications such
as batteries for gun-fired munitions including guided and smart,
mortars, fusing mines, missiles, and many other military and
commercial applications. The electrochemical reserve-type batteries
can in general be divided into two different basic types.
[0004] The first type includes the so-called thermal batteries,
which are to operate at high temperatures. Unlike liquid reserve
batteries, in thermal batteries the electrolyte is already in the
cells and therefore does not require a release and distribution
mechanism such as spinning. The electrolyte is dry, solid and
non-conductive, thereby leaving the battery in a non-operational
and inert condition. These batteries incorporate pyrotechnic heat
sources to melt the electrolyte just prior to use in order to make
them electrically conductive and thereby making the battery active.
The most common internal pyrotechnic is a blend of Fe and
KClO.sub.4. Thermal batteries utilize a molten salt to serve as the
electrolyte upon activation. The electrolytes are usually mixtures
of alkali-halide salts and are used with the Li(Si)/FeS.sub.2 or
Li(Si)/CoS.sub.2 couples. Some batteries also employ anodes of
Li(Al) in place of the Li(Si) anodes. Insulation and internal heat
sinks are used to maintain the electrolyte in its molten and
conductive condition during the time of use.
[0005] The second type includes the so-called liquid reserve
batteries in which the electrodes are fully assembled for
cooperation, but the liquid electrolyte is held in reserve in a
separate container until the batteries are desired to be activated.
In these types of batteries, since there is no consumption of the
electrodes under these circumstances, the shelf life of the
batteries is essentially unlimited. The battery is activated by
transferring the electrolyte from its container to the battery
electrode compartment (hereinafter referred to as the "battery
cell").
[0006] A typical liquid reserve battery is kept inert during
storage by keeping the aqueous electrolyte separate in a glass or
metal ampoule or in a separate compartment inside the battery case.
The electrolyte compartment may also be separated from the
electrode compartment by a membrane or the like. Prior to use, the
battery is activated by breaking the ampoule or puncturing the
membrane allowing the electrolyte to flood the electrodes. The
breaking of the ampoule or the puncturing of the membrane is
achieved either mechanically using certain mechanisms or by the
high-G firing setback shock. In these batteries, the projectile
spin or a wicking action of the separator is generally used to
transport the electrolyte into the battery cells.
[0007] In recent years, there have been a number of advancements in
reserve battery technologies. Among these advances are
superhydrophobic nanostructured materials, bimodal lithium reserve
battery, and ceramic fiber separator for thermal batteries. In one
liquid reserve battery technology under development,
"superhydrophobic nanostructured material" is used in a honeycomb
structure to keep the electrolyte separated from the battery cell.
"Electrowetting" is achieved by the application of a trigger
voltage pulse. The electrolyte can then penetrate the honeycomb
structure and come into contact with the electrodes, thereby making
the cell electrochemically active.
[0008] The currently available liquid reserve and thermal batteries
of all types and configurations and those that are known to be
under development suffer from several basic shortcomings for many
current and future munitions applications, including the following:
[0009] 1. The main shortcoming of currently available liquid
reserve batteries of all types and configurations is their very
poor performance at low temperatures, usually below -25 deg. F and
for becoming almost non-functional at lower temperatures. In most
munition applications, however, the batteries are required to be
operational at significantly lower temperatures of -40 deg. F and
sometimes lower, and sometimes after storage at temperatures as low
as -65 deg. F. [0010] 2. Another shortcoming of all currently
available liquid reserve batteries is activation at very low
temperatures. [0011] 3. Another shortcoming of all currently
available liquid reserve batteries is their relatively slow rise
time, particularly at low temperatures. Researchers have, however,
attempted to minimize this shortcoming by, for example, by
injecting pressurized electrolyte into the battery cells; using
wicks to increase the electrolyte diffusion rate; utilize spin
and/or setback to move electrolyte into the battery cell to
increase; etc. These methods have improved the liquid reserve
battery rise time to but not significantly enough to address all
applications and in many applications such solutions are not even
practical. [0012] 4. Thermal reserve batteries do not have low
temperature issues and can be activated and produce power at even
below -100 deg. F. However, thermal batteries have very short run
time, particularly for smaller sizes that are required in gun-fired
munitions in which the run time might become even less than one
minute. [0013] 5. Currently available liquid reserve and thermal
reserve batteries have both the shortcoming of not being able to be
reverted to their reserve state once they have been activated. This
capability is highly desirable for many munitions and other
emergency powering applications in which different amounts of
electrical power may be needed at different times with periods in
between, which might be very long, during which no power is
needed.
[0014] In current lithium metal-based liquid reserve batteries,
such as lithium thionyl chloride and lithium graphite fluoride,
rely on the supply of a liquid electrolyte to the cathode electrode
at the time of activation. This requires the storage of the liquid
electrolyte separately from the rest of the battery mostly inside
glass ampoules, which are broken in the process of activation. The
liquid electrolytes have also been stored in metal bellows with
provided membranes or have been separated from the battery core by
certain membranes, which in either case is ruptured during the
activation process. In general, the activation process is
relatively slow, resulting in relatively slow power rise time, and
face distribution issues inside the battery core, particularly at
low temperatures.
[0015] There are only a few battery chemistries that have the
potential chance of achieving significantly higher energy density
than is currently available for reserve batteries. The main
candidates for achieving significantly higher energy density for
reserve batteries are metal-air based battery systems, FIG. 1. The
most common type of commercial metal-air battery utilizes zinc-air
chemistry and has a practical specific energy of .about.370 Wh/kg,
while this battery chemistry has a theoretical specific energy of
1350 Wh/kg. In addition to zinc-air batteries, aluminum-air
batteries are also available in the commercial market, although
only in a limited fashion. Aluminum-air batteries have a much
greater theoretical specific energy (8140 Wh/kg) and although they
currently have a practical specific energy of .about.350 Wh/kg but
have the potential for significant specific energy improvement. The
highest theoretical specific energy for a metal-air battery
chemistry is lithium-air at 11,500 Wh/kg giving it and aluminum-air
batteries the best potential to realize significantly higher
specific energy values for reserve batteries as compare to the
currently available reserve batteries.
[0016] In a primary Metal-Oxygen battery, oxygen gas reacts with
the metal ions on the porous carbon substrate cathode. There is a
clear advantage of Metal-Oxygen batteries over traditional liquid
primary reserve batteries in that the activation mechanism of the
former does not require the injection of a liquid electrolyte but
of oxygen gas. While Metal-Oxygen batteries do still require of a
liquid electrolyte to transport the metal ions from the metal anode
to the cathode electrode during battery discharge, the liquid
electrolyte on its own does not activate the battery and hence it
can then be added to the battery during the assembly process. Since
the activation of the battery relies on the transport of a gas, and
not of a liquid, into the porous cathode material, the rate of
activation for Metal-Oxygen batteries is much faster and more
efficient than that of the traditional liquid reserve batteries. If
the metal used in the battery is lithium, and since the theoretical
energy density of Li-Oxygen batteries is the highest of all lithium
metal batteries (11,500 Wh/kg of lithium, excluding the oxygen
mass), therefore primary reserve Li-Oxygen batteries have the
potential to be significantly more energy dense than the
traditional liquid reserve batteries.
[0017] A primary reserve battery based on Metal-Oxygen chemistry is
activated by allowing oxygen gas to enter the porous cathode
material. The metal in the battery can be one of those indicated in
FIG. 1 and more, i.e., lithium, sodium, potassium zinc, magnesium,
calcium, aluminum, iron, silicon, germanium, and tin.
[0018] A lithium-air battery has three main components: an anode,
an electrolyte, and a cathode, FIG. 2. The anode is the source of
lithium-ions and can be lithium metal. The electrolytes can be
e.g., aqueous, aprotic (organic), mixed aqueous/aprotic, or solid
state, each having its own advantages and disadvantages. The
lithium-air battery also includes the cathode, which as is stated
in the name of this technology, is air--or more accurately stated,
the oxygen in the air. Being that the cathode materials is supplied
by the oxygen in the air the mass of the cathode is very small,
thus imparting a significant savings in the mass of the overall
system and the theoretical specific energy. However, the oxygen
still needs a platform for the electrochemical reactions of the
battery to take place. These reactions can be supported by the use
of porous carbon materials that are in some cases coated with a
catalytic metal oxide, such as MnO.sub.2 or CoO.sub.2.
[0019] Reserve Lithium-air batteries are primary batteries. In
general, the lithium air battery includes a lithium metal anode
electrode capable of generating lithium ions during discharge and a
cathode containing oxygen in the air as a cathode active material,
and a lithium ion conductive medium (electrolyte) is provided
between the cathode and anode. The lithium air primary battery has
a theoretical energy density of 3000 Wh/kg or more, which
corresponds to about 10 times energy density of a lithium ion
battery. In addition, the lithium air battery may be eco-friendly
and provide improved stability as compared to the lithium ion
battery.
SUMMARY
[0020] Therefore, reserve batteries based on Lithium-air battery
operation mechanism would provide significantly higher energy
density than is available from all current liquid reserve
batteries. Such reserve batteries must, however, be suitable for
use in gun-fired and other munitions, for example, should be
capable of withstanding high firing shock loadings and have shelf
life of over 20 years.
[0021] It is also highly desirable that such higher density reserve
batteries be capable of being activated and deactivated, i.e.,
reverted to its reserve state, in order to significantly increase
the run time of the battery when the power demand varies
significantly over time, particularly when for very long periods of
times very small or no power may be needed for the battery to
provide.
[0022] A need therefore exists for reserve batteries that can
provide electrical energy to munitions for relatively long run time
that is currently possible with thermal batteries and liquid
reserve batteries.
[0023] A need also exists for reserve batteries that can be
activated and deactivated and reverted to their pre-activation
reserve state.
[0024] In particular, there is a need for reserve batteries with
shelf life of over 20 years that can provide power to low power
electronics over long periods of times that could extend for days,
weeks and even months. It is appreciated by those skilled in the
art that to achieve such long shelf life, the battery components
can be hermetically sealed inside the reserve battery housing.
[0025] A need also exists for reserve batteries with significantly
higher energy density that the currently available reserve
batteries.
[0026] A need also exists for reserve batteries that can be
activated very rapidly to provide electrical energy.
[0027] Such reserve batteries can be initiated as a result of the
munitions firing using inertial igniters, such as those disclosed
in U.S. Pat. Nos. 7,437,995; 7,587,979; 7,587,980; 7,832,335 and
8,061,271 and U.S. patent application Ser. Nos. 12/774,324;
12/794,763; 12/835,709; 13/180,469; 13/207,280 and 61/551,405, the
full disclosure of each of which being incorporated herein by
reference, or piezoelectric-based inertial igniters, such as those
disclosed in U.S. Pat. No. 8,024,469 and U.S. patent application
Ser. Nos. 13/186,456 and 13/207,355, the full disclosure of each of
which being incorporated herein by reference) or other electrical
initiators. The piezoelectric-based inertial igniters, such as
those that can provide relatively long initiation delay, can delay
or eliminate the time period in which the battery is subjected to
high acceleration/deceleration levels. The reserve battery may also
be activated following launch when its power is needed, which may
in certain cases be long after launch and even after landing. The
initiation devices to be used can also be configured to operate
safely by differentiating all-fire and various no-fire events, such
as accidental drops and vibration and impact during transportation
and loading and even nearby explosions. The task of differentiating
all-fire conditions from no-fire conditions can be performed
without the use of external acceleration sensors and the like,
and/or the use of external power sources.
[0028] An objective is to provide new types of reserve batteries
(power sources) that can operate efficiently at low temperatures
and that can be activated and brought to operational power levels
rapidly. Such reserve batteries can also be fabricated in small
sizes suitable for use in small and medium caliber munitions,
sub-munitions and the like.
[0029] Another objective is to provide new types of reserve
batteries that can be activated and deactivated, i.e., reverted to
their reserve battery state, as needed for powering the intended
electrical energy consuming devices.
[0030] Another objective is to provide new types of reserve
batteries and methods of providing smart and programmable power
systems that can maximize the overall efficiency of the power
system and thereby minimize the total volume of the power system,
such as for munitions applications.
[0031] Another objective is to provide new types of reserve
batteries that can be rapidly activated using electrical or
inertial activation devices to provide electrical energy as needed
and become deactivated, i.e., be reverted to its reserve state,
when it does not have to provide electrical energy, to extend its
useful service period of time as much as possible.
[0032] To ensure safety and reliability, the reserve batteries can
withstand and not initiate during acceleration events which may
occur during manufacture, assembly, handling, transport, accidental
drops, etc. Additionally, once under the influence of an
acceleration profile indicating firing of the ordinance, i.e., an
all-fire condition (with or without a programmed delay period), the
reserve battery should initiate with high reliability.
[0033] The disclosed reserve power sources can be provided with
hermetically sealed packaging. As such, the disclosed reserve power
sources would be capable of readily satisfying most munitions
requirement of 20-year shelf life requirement and operation over
the military temperature range of -65 to 165 degrees F., while
withstanding high G firing accelerations.
[0034] In many applications, the reserve battery can provide full
or close to full power very short time after initiation. This
capability can be challenging when the reserve battery is at very
low temperatures, such as the aforementioned -65 degrees F.
[0035] There is a clear advantage for the development of reserve
batteries that can use Lithium-air primary battery technologies
over liquid reserve batteries and thermal batteries as was
previously described. For the case of liquid reserve batteries, the
main advantages include the elimination of separate liquid
electrolyte storage and a significant increase in the amount of
electrical energy that can become available per unit volume, which
are of particular importance in applications such as munitions.
While Li-Air batteries may still require a liquid electrolyte to
transport the lithium ions from the lithium metal anode to the
cathode electrode during battery discharge, the liquid electrolyte
on its own does not activate the battery and hence it can then be
added to the battery during the battery assembly process. In
addition, since activation of the battery relies on the transport
of a gas and not of a liquid into the porous cathode material, the
rate of activation for Li-Air batteries is much faster and
efficient than that of the traditional liquid reserve batteries.
Moreover, since the theoretical energy density of Li-Air batteries
is the highest of all lithium metal batteries, Li-Air based reserve
batteries have the potential to be capable of providing
significantly more electrical energy than currently available
liquid reserve batteries can provide.
[0036] Accordingly, methods and apparatus are provided for reserve
batteries that are based on Lithium-Air technology and have long
shelf life of over 20 years.
[0037] Furthermore, methods and apparatus are provided for reserve
batteries that can be activated and deactivated and reverted to
their reserve state on command or via a self-regulated
mechanism.
[0038] Furthermore, methods and apparatus are provided for
activation of reserve batteries when subjected to a prescribed gun
or the like firing accelerations as described by a shock loading
level and its duration and that it does not activate under
prescribed accidental shock loadings such as drop over hard
surfaces or due to transportation vibration and other similar
(non-activation) events.
[0039] Furthermore, methods and apparatus are provided for
activation of reserve batteries based on external commands, which
can be initiated based on a pre-programmed plan or a sensory or
certain event detection or the like.
[0040] It is appreciated by those skilled in the art that since
Lithium-Oxygen batteries has the potential of providing reserve
batteries with the highest energy density, hereinafter the
different embodiments are described herein in terms of
Lithium-Oxygen reserve batteries without any intention of limiting
the disclosed embodiments to Lithium metal and in general, any
other metal, including those disclosed above may be used to replace
the Lithium metal as the anode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] These and other features, aspects, and advantages of the
apparatus of the present invention will become better understood
with regard to the following description, appended claims, and
accompanying drawings where:
[0042] FIG. 1 illustrates theoretical specific energies of various
metals known in the prior art which can be used in metal-air
battery technology.
[0043] FIG. 2 illustrates basic components of a Lithium-Air battery
of the prior art.
[0044] FIG. 3 illustrates a cross-sectional view of a first
embodiment of the Lithium-Oxygen reserve battery.
[0045] FIG. 4 illustrates a cross-sectional view of an alternative
activation mechanism assembly in the Lithium-Oxygen reserve battery
embodiment of FIG. 3.
[0046] FIG. 5 illustrates a cross-sectional view of another
embodiment of a Lithium-Oxygen reserve battery configured for
activation manually or using an externally positioned actuation
device.
[0047] FIG. 6 illustrates a cross-sectional view of an alternative
activation mechanism assembly of the embodiment of FIG. 5 in the
Lithium-Oxygen reserve battery core.
[0048] FIG. 7 illustrates a cross-sectional view of an embodiment
of Lithium-Oxygen reserve battery configured to allow activation
and deactivation of the reserve battery manually or via an
externally positioned actuation device.
[0049] FIG. 8 illustrates a blow-up view "A" of FIG. 7 showing
details of one mechanism for activating and deactivating the
reserve battery.
[0050] FIGS. 8A and 8B illustrate a method of providing the
Lithium-Oxygen reserve batteries with external bellow activation
mechanisms with "safety pin" to prevent for accidental
activation.
[0051] FIG. 9 illustrates a cross-sectional view of another
embodiment of Lithium-Oxygen reserve battery configured to be
activated when subjected to a prescribed acceleration profile.
[0052] FIG. 10 illustrates a cross-sectional view of another
embodiment of Lithium-oxygen reserve battery configured for an
initial activation when subjected to a prescribed acceleration
profile and for consequent activation/deactivation on command.
[0053] FIG. 11 illustrates a cross-sectional view of another
embodiment of Lithium-oxygen reserve battery that can be initially
activated inertially when subjected to a prescribed acceleration
profile or from external power and for consequent
activation/deactivation on command.
[0054] FIG. 12 illustrates a cross-sectional view of another
embodiment of Lithium-oxygen reserve battery configured for user
mounted activation/deactivation on command.
[0055] FIG. 13A illustrates a blow-up view "B" of the oxygen gas
valve of the Lithium-oxygen reserve battery embodiment of FIG.
12.
[0056] FIG. 13B illustrates an alternative oxygen gas valve for the
Lithium-oxygen reserve battery embodiment blow-up "B" of FIG. 12
configured for activation when subjected to a prescribed
acceleration profile and staying activated.
[0057] FIG. 13C illustrates an alternative oxygen gas valve for the
Lithium-oxygen reserve battery embodiment blow-up "B" of FIG. 12
configured for activation when subjected to a prescribed
acceleration profile and be activated and deactivated and/or stay
activated on command.
[0058] FIG. 14 illustrates a cross-sectional view of another
embodiment of Lithium-oxygen reserve battery configured for
activation by initiation of a pyrotechnic charge that is ignited
electrically.
[0059] FIG. 15 illustrates a cross-sectional view of an example of
a modified activation mechanism for the embodiment of FIG. 7.
[0060] FIG. 16 illustrates a cross-sectional view of another
embodiment of Lithium-oxygen reserve battery configured for
activation when subjected to a prescribed acceleration profile.
DETAILED DESCRIPTION
[0061] The present Li-Oxygen reserve batteries are described using
the basic Li-Oxygen reserve battery embodiment 10 shown in the
cross-sectional schematic of FIG. 2. As discussed above, such
Li-Oxygen reserve battery is presented by way of example and
without any intention of limiting the disclosed embodiments to
Lithium metal and in general, any other metal, including those
disclosed above may be used to replace the Lithium metal as the
anode.
[0062] As can be seen in FIG. 3, the reserve battery embodiment 10
comprises a metal anode, such as a Lithium metal electrode that is
separated from the battery non-aqueous electrolyte by a Solid
Electrolyte Interphase (SEI) layer. A porous cathode, such as a
Carbon-based O.sub.2 cathode is the next component of the battery
core into which a gas such as Oxygen gas or a gas containing Oxygen
can be allowed to enter to activate the reserve battery. The above
components of the Li-Oxygen reserve battery are packaged inside a
sealed housing 11. To achieve a hermetically sealed reserve battery
with a shelf life of over 20 years, the battery terminals 12 can be
provided with glass or other similar electrical insulation as they
pass through the sealed housing 11.
[0063] In another sealed housing compartment 18, oxygen gas is
provided under pressure as shown in FIG. 3. The sealed compartment
18 and the battery core housing 11 can share a common wall 19. The
common wall 19 can be provided with a relatively small opening 14
into the battery core, which can be sealed by a metallic diaphragm
13. In general, the housings 11 and 18 can be formed from stainless
steel and the diaphragm 13 can also be a thin stainless sheet that
is welded to the wall 19.
[0064] Also provided inside the oxygen gas compartment 18 is a
movable mass member 15, which can be biased firmly against surface
21 of the compartment 18, such as, by a preloaded compressive
spring 16. The mass member 15 can be provided with a sharp cutting
member 17, which is positioned above the hole 14.
[0065] The Li-Oxygen reserve battery embodiment 10 operates as
follows. In normal conditions, the diaphragm 13 prevents oxygen gas
from entering the porous carbon-based O.sub.2 cathode of the
battery core. If the device to which the reserve battery 10 is
attached is accelerated in the direction of arrow 22, the
acceleration would act on the mass member 15, generating a downward
dynamic force. The compressive spring 16 is preloaded such that
when the acceleration in the direction of the arrow 22 has reached
a prescribed threshold, then the generated dynamic force would
overcome the spring preload and the mass member 15 would begin to
move downward towards the diaphragm 13. If the acceleration in the
direction of the arrow 22 is long enough in duration, the mass
member 15 would gain enough speed for the cutting member 17 to
reach the diaphragm 13 and rupture it, thereby allowing the oxygen
gas to begin to flow into the porous carbon-based O.sub.2 cathode
section of the battery core and activate the reserve battery. If
the duration of the applied acceleration in the direction of the
arrow 22 is very short, for example due to accidental drop of the
object to which the reserve battery 10 is attached, the mass member
15 and spring 16 system is configured such that the cutting member
17 is not displaced down enough to rupture the diaphragm 13.
[0066] In the schematic of FIG. 3 only one inertia-based activation
mechanism is shown to be provided. It is appreciated that when a
larger amount of gas flow is desired, more than one activation
mechanism of this type or another type and corresponding hole 14
and diaphragm 13 may also be provided.
[0067] It is appreciated by those skilled in the art that gases
present in air, such as nitrogen, water vapor, and carbon dioxide
can react with the metal anode, liquid electrolyte, and cathode
electrode and negatively impact the discharge performance of
currently available Lithium-Air batteries. In addition, it has been
extensively reported (for example, J. Read, K. Mutolo, M. Ervin, W.
Behl, J. Wolfenstine, A. Driedger and D. Foster, "Oxygen Transport
Properties of Organic Electrolytes and Performance of
Lithium/Oxygen Battery," Journal of Electrochemical Society, vol.
150, no. 10, pp. A1351-A1356, 2003) that a higher oxygen partial
pressure improves battery capacity, especially at high discharge
rates, by increasing the oxygen saturation concentration in the
liquid electrolyte and by enhancing the oxygen diffusion rates in
the porous cathode active sites. Therefore, pure oxygen can be used
in the compartment 18 to activate and discharge the battery.
[0068] The reserve battery embodiment 10 of FIG. 1 is assembled in
the inactive state with the pressurized oxygen in the adjacent
compartment 18. As a result, as long as oxygen gas is not allowed
to enter the battery core through the provided hole 14 by the
diaphragm 13, the battery stays in its inactive state, thus serving
as a reserve battery. Once the diaphragm 13 has been ruptured as
was previously described, the presence of oxygen immediately starts
the reduction/oxidation reactions inside the battery core and, as a
result, a voltage differential is established across the anode and
cathode sides of the cell. In the porous carbon cathode electrode,
oxygen is reduced to lithium peroxide that accumulates in the pores
of the electrode. At the same time, lithium metal from the anode
electrode is oxidized to lithium ions, which transport to the
cathode electrode through the liquid electrolyte and polymeric
separator to the porous carbon cathode electrode. The battery
discharge reactions will continue until all the stored oxygen or
the available Li metal is consumed.
[0069] In the Lithium-Oxygen embodiment 10 of FIG. 3, the
mass-spring based inertial activation mechanism of the battery is
positioned inside the pressurized oxygen comportment of the
battery. An alternative positioning of the mass-spring inertial
based activation mechanism inside the porous carbon-based O.sub.2
cathode side of the reserve battery assembly is shown in the
cross-sectional view of FIG. 4 and indicated as the reserve battery
embodiment 20. In the schematic of FIG. 4, all other components of
the reserve battery are similar to that of the embodiment 10 of
FIG. 3. It is appreciated that to support the preloaded compressive
spring 24 of the mass-spring based inertial activation mechanism, a
support structure 23, for example a beam structure 23 or a base
support structure 25 must be provided.
[0070] One advantage of locating the mass-spring based inertial
activation mechanism inside the battery core may be that it makes
the battery assembly easier and allows more space for the
pressurized oxygen.
[0071] The Li-Oxygen reserve battery embodiment 20 of FIG. 4
operates as follows. In normal conditions, the diaphragm 13
prevents oxygen gas from entering the porous carbon-based O.sub.2
cathode of the battery core. If the device to which the reserve
battery 20 is attached is accelerated in the direction of the arrow
26, the acceleration would act on the mass member 27, which is
movable within the housing 11, generating a downward dynamic force.
The compressive spring 24 is preloaded such that when the
acceleration in the direction of the arrow 26 has reached a
prescribed threshold, then the generated dynamic force would
overcome the spring preload and the mass member 27 would begin to
move upward as viewed in FIG. 4 and towards the diaphragm 13. If
the acceleration in the direction of the arrow 26 is long enough in
duration, the mass member 27 would gain enough speed for the
cutting member 28 to reach the diaphragm 13 and rupture it, thereby
allowing the oxygen gas to begin to flow into the porous
carbon-based O.sub.2 cathode section of the battery core and
activate the reserve battery. If the duration of the applied
acceleration in the direction of the arrow 26 is very short, for
example due to accidental drop of the object to which the reserve
battery 20 is attached, the mass member 27 and spring 24 system is
configured such that the cutting member 28 is not displaced up
enough to rupture that diaphragm 13.
[0072] The Lithium-Oxygen reserve battery embodiments 10 and 20 of
FIGS. 3 and 4, respectively, are configured to be activated when
the device to which they are attached is subjected to a prescribed
acceleration profile, such as firing of a gun. In certain
applications, however, the reserve battery is required to be
activated manually or via certain actuation device that is
positioned external to the reserve battery. The reserve battery
embodiment 30 of FIG. 5 is configured to allow for activation
manually or using an external positioned actuation device.
[0073] In the schematic of FIG. 5, all other components of the
reserve battery are similar to that of the embodiment 10 of FIG. 3,
except that its mass-spring inertial activation mechanism is
removed and is replaced by a mechanism that allows for manual
activation or using an externally positioned actuation device as
described below.
[0074] As can be seen in FIG. 5, the Lithium-Oxygen reserve battery
embodiment 30 is provided with an activation mechanism comprising a
metallic bellow 31, such as that formed with the same metal with
which the container 18 is constructed, such as stainless steel. The
bellow 31 is fixedly attached to the top surface of the oxygen gas
container 18, such as by welding or brazing, and the attachment is
tested to ensure that is fully sealed. The bellow is configured to
have the required flexibility so that when pressed to activate the
battery as described below, it would essentially act as a spring
element and return to its normal state. The bellow is provided with
a sealed cap 33, which may be integral to the bellow 31. A pin 34
is fixedly attached to the cap 33 of the bellow 31, which can be
provided with a guide 36 inside the oxygen gas container 18 as can
be seen in FIG. 5. The pin 34 is provided with a sharp tip 35,
which is positioned over the hole 14 and proximate to the diaphragm
13.
[0075] The Li-Oxygen reserve battery embodiment 30 of FIG. 5
operates as follows. In normal conditions, the diaphragm 13
prevents oxygen gas from entering the porous carbon-based O.sub.2
cathode of the battery core. The user then may manually press the
cap 33 of the bellow 31 down in the direction of the arrow 37. As a
result, the bellow 31 begins to deform, allowing the pin 34 to
slide down the guide 36, causing the sharp tip 35 of the pin 34 to
rupture the diaphragm 13, thereby allowing the oxygen gas to begin
to flow into the porous carbon-based O.sub.2 cathode section of the
battery core and activate the reserve battery. It is appreciated by
those skilled in the art that the cap 33 of the bellow 31 may also
be displaced down by an externally positioned linear or rotary
electrical, piezoelectric-based or pneumatic or the like actuation
device on command, for example provided by a system control system,
as is well known in the art.
[0076] In the Lithium-Oxygen embodiment 30 of FIG. 5, the manual or
externally actuated activation mechanism of the battery is
positioned at the pressurized oxygen comportment of the battery and
must therefore be capable of withstanding the oxygen gas pressure
while staying fully sealed. An alternative positioning of the
activation mechanism is inside the porous carbon-based O.sub.2
cathode side of the reserve battery assembly as shown in the
cross-sectional view of FIG. 6. The resulting Lithium-Oxygen
reserve battery is indicated as the embodiment 40. In the schematic
of FIG. 6, all other components of the reserve battery are similar
to that of the embodiment 10 of FIG. 3. Another advantage of
locating the activation mechanism inside the battery core is that
it makes the battery assembly easier and allows more space for the
pressurized oxygen.
[0077] As can be seen in FIG. 6, the Lithium-Oxygen reserve battery
embodiment 40 is provided with an activation mechanism that
comprises a metallic bellow 41, such as being formed of the same
metal with which the battery core housing 11 is constructed, such
as stainless steel. The bellow 41 is fixedly attached to the side
surface of the battery core housing 11, such as by welding or
brazing, and the attachment is tested to ensure that is fully
sealed. The bellow 41 is provided with a sealed cap 42, which may
be integral to the bellow 41. A pin 43 is fixedly attached to the
cap 42 of the bellow 41, which can be provided with a guide 44
inside the battery core housing 11 as can be seen in FIG. 6. The
pin 43 is provided with an enlarged frontal section 45 that is
movable within the housing 11 and that is close or in contact with
the flexible member 46 that bends as a bending flexure or rotates
about a joint and on which is provided a sharp tip member 47, which
is positioned under the hole 49 and proximate to the diaphragm 48
as can be seen in FIG. 6.
[0078] The Li-Oxygen reserve battery embodiment 40 of FIG. 6
operates as follows. In normal conditions, the diaphragm 48
prevents oxygen gas from entering the porous carbon-based O.sub.2
cathode of the battery core. The user then may manually press the
cap 42 of the bellow 41 in the direction of the arrow 51. As a
result, the bellow 41 begins to deform, allowing the pin 43 to
slide in the guide 44, causing the sharp tip 45 of the pin 43 to
bend/rotate the member 46 upward towards the diaphragm 48, thereby
causing the sharp tip member 47 to rupture the diaphragm 48,
thereby allowing the oxygen gas to begin to flow into the porous
carbon-based O.sub.2 cathode section of the battery core and
activate the reserve battery. It is appreciated by those skilled in
the art that the cap 42 of the bellow 41 may also be displaced down
by an externally positioned linear or rotary electrical or
piezoelectric-based or pneumatic or the like actuation device on
command, for example provided by a system control system, as is
well known in the art.
[0079] It is appreciated that once the novel Lithium-Oxygen reserve
battery embodiments of FIGS. 3-6 are activated, they would
generally stay activated until it runs out of either oxygen gas or
Lithium metal. In many applications in which electrical energy may
only be needed for relatively short periods of times and relatively
long enough times in between, then it is highly desirable for a
reserve battery to be capable of being activated only when needed
and then be deactivated, i.e., reverted to its reserve battery
state. The reserve batteries are herein described as if it is
implemented in the Lithium-oxygen reserve battery embodiment 50 of
FIG. 7.
[0080] In the schematic of FIG. 7, all components of the
Lithium-oxygen reserve battery are similar to that of the
embodiment 10 of FIG. 3, except that its mass-spring inertial
activation mechanism is removed and is replaced by the
activation/deactivation mechanism shown in the blow-up view "A",
which is illustrated in detail in FIG. 8.
[0081] As can be seen in the blow-up view "A" of FIG. 8, the
Lithium-Oxygen reserve battery embodiment 50 is provided with an
activation mechanism comprising two components. The first component
is the actuation mechanism that comprises a metallic bellow 52,
that can be formed of the same metal with which the battery core
housing 11 (FIG. 7) is constructed, such as stainless steel. The
bellow 52 is fixedly attached to the side surface of the battery
core housing 11, such as by welding or brazing, and the attachment
is tested to ensure that is fully sealed. The bellow 52 is provided
with a sealed cap 53, which may be integral to the bellow 52. A pin
54 is fixedly attached to the cap 53 of the bellow 52, which can be
provided with a guide 55 inside the battery core housing 11 as can
be seen in FIG. 8. The pin 54 is provided with an enlarged frontal
conical section 56 that is close or in contact with a sloped
surface 57 of the member 58 as shown in FIG. 8.
[0082] The second component of the actuation mechanism is a
normally closed valve 59. The normally closed valve 59 comprises a
valve cap 61, which is provided with a stem member 62 that passes
through a hole that is provided in the base 64 of the oxygen gas
container 18, FIG. 7. The opposite side of the stem member 62 is
provided with the member 58, which is used to provide support for
the preloaded compressive spring 65 and its bottom surface 57 is
sloped as can be seen in FIG. 8 to engage the surface of the
conical section 56 of the actuation mechanism. An elastomeric
gasket 63 is also provided between the surface of the oxygen gas
container surface 64 and a surface of the valve cap 61. The
compressive spring 65 is preloaded enough to ensure that in its
normally closed state, no oxygen gas can escape into the battery
core from the pressurized oxygen container 18. The pressurized
oxygen gas itself also assists in sealing of the valve in its
normally closed state.
[0083] The Li-Oxygen reserve battery embodiment 50 of FIG. 7
operates as follows. In normal conditions, the valve 59 is closed
and prevents oxygen gas from entering the porous carbon-based
O.sub.2 cathode of the battery core. The reserve battery 50 is
therefore in its inactive state and provides a long shelf life that
can significantly exceed the military required 20 years. The user
may then manually press the cap 53 of the bellow 52 in the
direction of the arrow 66, FIG. 8. As a result, the bellow 52
begins to deform, allowing the pin 54 to slide forward in the guide
55, causing the conical section 56 to move forward, thereby
engaging the sloped surface 57 of the member 58 and forcing it to
begin to move upward as seen in the view of FIG. 8. As a result,
the cap 61 is lifted from over the elastomeric gasket 63, thereby
allowing the oxygen gas to begin to flow into the porous
carbon-based O.sub.2 cathode section of the battery core and
activate the reserve battery. When the applied force to the cap 53
of the bellow 52 in the direction of the arrow is removed, the
compressed bellow 52 would spring back (which might be assisted by
an internal compressive spring that is provided around the pin 54
inside the bellow--not shown), thereby allowing the preloaded
compressive spring 65 and the pressurized oxygen gas to close the
valve 59 and stop transfer of pressurized gas into porous
carbon-based O.sub.2 cathode section of the battery core. The
battery is thereby reverted to its reserve state and the battery
core would stop generating electrical energy once its present
oxygen gas has been consumed.
[0084] It is appreciated by those skilled in the art that the cap
53 of the bellow 52, FIG. 8, may also be displaced forward in the
direction of the arrow 66 by an externally positioned linear or
rotary electrical or piezoelectric-based or pneumatic or the like
actuation device on command, for example provided by a system
control system, as is well known in the art.
[0085] It is noted that in the embodiments 30, 40 and 50 of FIGS.
5, 6 and 7, respectively, the activation mechanism bellow is
positioned outside of the reserve battery housing. Such positioning
of the activation device bellow may then be used to provide a
"safety pin" for the reserve battery to protect it against
accidental activation, such as during the battery fabrication and
packaging and during the process of installing in the final
product. The "safety pin" may in general be positioned between the
bellow cap (33, 42 and 53 in FIGS. 5, 6 and 8, respectively) and
the outer surface of the reserve battery. An example of such a
bellow actuation preventing "safety pin" as applied to the
activation mechanism of the reserve battery embodiment 30 of FIG. 5
is shown in the schematics of FIG. 8A and the top view of FIG.
8B.
[0086] In the schematic of FIG. 8A the reserve battery activation
mechanism of the Lithium-Oxygen reserve battery embodiment 30 of
FIG. 5 as mounted on the top surface 145 (32 in FIG. 5) of the
oxygen gas container 146 is shown. As was described for the
embodiment of FIG. 5, the bellow 140 (31 in FIG. 5) is fixedly
attached to the surface 145. The bellow 140 is provided with a
sealing cap 143, which is larger than the cap 33 of the embodiment
of FIG. 5. The sliding pin 144 (34 in FIG. 5) with the sharp tip is
also shown in FIG. 8A. The "safety pin" of the activation mechanism
comprises a "U" shaped member 147, which is positioned around the
bellow 140 and under the edges 148 of the cap 143 as can be seen in
FIG. 8A and the top view of FIG. 8B. It is noted that FIG. 8A is
the cross-sectional view C-C of FIG. 8B. The "U" shaped member 147
would then prevent accidental depression of the cap 143 and thereby
accidental activation of the reserve battery. A pin 149 can also be
provided that passes through matching holes (not seen in FIG. 8A)
through the ends of the "U" shaped member 147 as shown in FIG. 8B
to prevent the "U" shaped member 147 from falling off as the
reserve battery is handled. With the described "safety pin"
assembly, the reserve battery is rendered non-operational. To make
the reserve battery operational, the user would pull the pin 149
out to allow the "U" shaped member 147 to be pulled out from under
the cap 143, thereby freeing the bellow 140 to be depressed to
rupture the membrane 13 (FIG. 5), thereby activating the reserve
battery as was previously described.
[0087] The valve 59 configuration may be readily adapted to provide
an inertial activation mechanism that does not rely on rupturing a
diaphragm, such as was described for the Lithium-oxygen reserve
battery embodiment 20 of FIG. 4. Such a Lithium-oxygen reserve
battery embodiment 60 is shown in the cross-sectional schematic of
FIG. 9. Such a Lithium-oxygen reserve battery embodiment 60 has two
basic advantages over the embodiment 20 of FIG. 4. The first
advantage is that it does not require the support structure (23 or
25 in FIG. 4). As a result, it makes the reserve battery
fabrication and assembly simpler. Secondly, since the pressurized
oxygen gas assists in keeping the valve closed and sealed, the
preloaded compressive spring is only required to provide a
relatively small force to keep the valve components together before
and after activation.
[0088] In the Lithium-Oxygen embodiment 60 of FIG. 9, the inertial
activation mechanism comprises a mass member 67, which is movable
in the housing 11 and which is connected to the valve cap 69 by a
connecting member 68 that passes through a hole provided in the
base of the pressurized oxygen gas container 18. An elastomeric
gasket 71 is provided under the valve cap 69 and is pressed down by
the preloaded compressive spring 72 and the pressure of the oxygen
gas to ensure that there is no leakage of the oxygen gas into the
battery core through the provided hole in the oxygen gas container.
A support member 73 is fixedly attached to the bottom surface 77 of
the pressurized oxygen gas container 18. A sliding member 74 is
then provided that is normally pressed slightly against the side of
the valve cap 74 by the preloaded compressive spring 75. All other
components of the Lithium-oxygen reserve battery embodiment 60 are
similar to that of the embodiment 10 of FIG. 3.
[0089] The Li-Oxygen reserve battery embodiment 60 of FIG. 9
operates as follows. In normal conditions, the preloaded
compressive spring 72 and the pressurized oxygen gas in the
container 18 keep the valve closed and prevent oxygen gas from
entering the porous carbon-based O.sub.2 cathode of the battery
core. If the device to which the reserve battery 60 is attached is
accelerated in the direction of the arrow 76, the acceleration
would act on the inertia of the mass member 67 and the connecting
member 68 and the cap 69, generating an upward dynamic force. The
compressive spring 72 is preloaded such that when the acceleration
in the direction of the arrow 76 has reached a prescribed
threshold, then the generated dynamic force would overcome the
spring preload and the assembly of the mass member 67, connecting
member 68 and the cap 69 would begin to move upward as viewed in
FIG. 9. If the acceleration in the direction of the arrow 76 is
long enough in duration, the cap 69 is moved up enough to allow the
pressurized oxygen gas to begin to flow into the porous
carbon-based O.sub.2 cathode section of the battery core and
activate the reserve battery. Once the cap 69 has moved up, the gap
between the bottom surface of the cap 69 and the surface 77 of the
container 18 is configured to be enough to allow the "locking"
member 74 to be pushed under the cap 69 and prevent the cap to
close the flow of the oxygen gas into the battery core once the
acceleration in the direction of the arrow 76 has ceased. Thereby,
the reserve battery is activated and stays activated after the
acceleration event, for example due to the firing of a munition in
which the reserve battery is mounted. If the applied acceleration
in the direction of the arrow 76 is below the prescribed threshold,
for example due to accidental drop of the object to which the
reserve battery 60 is attached, the valve stays closed and the
reserve battery is not activated.
[0090] It is appreciated that the Lithium-oxygen reserve battery
embodiment 50 of FIG. 7 can be activated using a linear or rotary
electrical or piezoelectric-based actuation device such as a
solenoid as was previously described. However, an external power
source is needed at the time of initial reserve battery activation.
This requirement may not be desirable in some munition
applications.
[0091] The Lithium-oxygen reserve battery embodiment 70 of FIG. 10
is configured to be activated during the munitions firing for a
short period of time to activate the reserve battery long enough to
generate the electrical energy needed to operate the electrically
actuated activation mechanism of the reserve battery as required by
the system being powered by the reserve battery.
[0092] In the Lithium-Oxygen reserve battery embodiment 70 of FIG.
10, the battery activation mechanism comprises the normally closed
valve 59, FIG. 8, and the actuation mechanism 84. The components of
the normally closed valve 59 are similar to that used in the
embodiment of FIG. 8. All other components of the Lithium-oxygen
reserve battery embodiment 70 are similar to that of the embodiment
10 of FIG. 3.
[0093] The actuation mechanism 84 of the Lithium-Oxygen reserve
battery embodiment 70 of FIG. 10 is similar to the one used in the
embodiment 50 of FIG. 7 (also shown in the blow up view of FIG. 8),
and similarly comprises a metallic bellow 78, such as being formed
of the same metal with which the battery core housing 11 (FIG. 10)
is constructed, such as stainless steel. The bellow 78 is fixedly
attached to the side surface of the battery core housing 11, such
as by welding or brazing, and the attachment is tested to ensure
that is fully sealed. The bellow 78 is provided with a sealed cap
79, which may be integral to the bellow 78. A connecting member 82
is fixedly attached to the cap 79 of the bellow 78, which is
provided with a guide 83 inside the battery core housing 11 as can
be seen in FIG. 10. The connecting member 82 is provided with an
enlarged frontal conical section mass member 81 (56 in FIG. 8) that
is close or in contact with the sloped surface 57 of the member 58
of the normally closed valve 59 as can also be seen in FIG. 8. A
preloaded tensile spring 86 may also be provided to ensure that in
normal conditions, the mass member does not force the valve 59 to
open. It is appreciated by those skilled in the art that instead of
the preloaded tensile spring 86, a preloaded compressive spring
(not shown) may be placed inside the bellow 78 to serve the same
function.
[0094] The Li-Oxygen reserve battery embodiment 70 of FIG. 10
operates as follows. In normal conditions, as can be seen in the
blow-up view of FIG. 8, the valve 59 is in its closed state and
prevents oxygen gas from entering the porous carbon-based O.sub.2
cathode of the battery core. In this state, the biasing forces of
the compressively preloaded spring 65 (FIG. 8) and the pressure of
the oxygen gas ensures that the valve 59 stays closed. The reserve
battery 70 is therefore in its inactive state and provides a long
shelf life that can significantly exceed the military required 20
years. If the device to which the reserve battery 70 is attached is
accelerated in the direction of the arrow 85, the acceleration
would act on the inertia of the mass member 81 and the connecting
member 82 and the cap 79, generating a downward dynamic force as
seen in the view of FIG. 10. The tensile spring 86 is preloaded
such that when the acceleration in the direction of the arrow 85
has reached a prescribed threshold, then the generated dynamic
force would overcome the spring preload and the assembly of the
mass member 81 and the connecting member 82 and the cap 79 would
begin to move down as viewed in FIG. 10. If the acceleration in the
direction of the arrow 85 is long enough in duration, the bellow 78
begins to deform, allowing the conical mass member 81 to move down,
thereby engaging the sloped surface 57 of the member 58 (FIG. 8)
and forcing it to begin to move to the right as seen in the view of
FIG. 10. As a result, the cap 61 is lifted from over the
elastomeric gasket 63 (FIG. 8), thereby allowing the oxygen gas to
begin to flow into the porous carbon-based O.sub.2 cathode section
of the battery core and activate the reserve battery. Then once the
acceleration in the direction of the arrow 85 has ceased, the mass
member 81 is forced to return to its pre-acceleration position
shown in FIG. 10 by the preloaded tensile spring 83 and the valve
59 is closed and the flow of oxygen gas into the battery core is
stopped.
[0095] If the applied acceleration in the direction of the arrow 85
is below the prescribed threshold, for example due to accidental
drop of the object to which the reserve battery 70 is attached, the
preloading level of the tensile spring 86 is not overcome, and the
mass member 81 dose not engage the sloped surface 57 of the member
58 and the valve 59 stays closed.
[0096] The Lithium-Oxygen reserve battery embodiment 70 of FIG. 10
is also provided with a linear or rotary electrical or
piezoelectric-based or the like actuation device, such as a
solenoid 80, which can be used to similarly apply an actuating
force to the cap 79 by its linearly displacing core 89 to open the
valve 59 as was described above to let an inflow of oxygen gas into
the battery core on demand. In the present embodiment 70, the
inertial activation in response to a prescribed acceleration
profile as was previously described is configured to allow enough
oxygen gas into the battery core to power the device electronics
and power control system and to operate the on/off activation
actuation device, in this case the solenoid 80.
[0097] In the Lithium-Oxygen reserve battery embodiment 70 of FIG.
10, the inertial activation in response to a prescribed
acceleration profile is configured to allow enough oxygen gas into
the battery core to power the device electronics and power control
system and to operate the on/off activation actuation device, in
this case the solenoid 80. Alternatively, the Lithium-Oxygen
reserve battery embodiment 70 may be paired with a capacitor (or
supercapacitor) 91, which is charged by the electrical energy
generated by the initial activation of the reserve battery. The
electrical energy stored in the capacitor 91 can then be used by
the object to which the reserve battery is attached (e.g., a gun
fired munition), and to re-activate the reserve battery as needed
by the actuator 80. Such a combined Lithium-Oxygen reserve battery
and capacitor (super-capacitor) reserve power sources are
hereinafter referred to as the "Lithium-Oxygen hybrid reserve
batteries."
[0098] It is appreciated that the Lithium-oxygen reserve battery
embodiment 70 of FIG. 10 is configured to be activated during the
munitions firing for a short period of time to activate the reserve
battery long enough to generate the electrical energy needed to
operate the electrically actuated activation mechanism of the
reserve battery as required by the system being powered by the
reserve battery. The actuation mechanism shown is the schematic of
FIG. 10 is a linear solenoid. However, other linear or rotary
electrical or piezoelectric-based or the like actuators may also be
used for this purpose. In the embodiment 70 of FIG. 10, the linear
solenoid actuation device is shown to be positioned external to the
reserve battery housing. In many munition applications, it is
highly desirable that all components of the reserve battery be
inside a hermetically sealed housing. To this end, the reserve
battery embodiment 70 is modified as described below to house all
externally positioned components of the reserve battery inside the
hermetically sealed battery housing as shown in the embodiment 90
of FIG. 11.
[0099] In the Lithium-Oxygen reserve battery embodiment 90 of FIG.
11, the battery activation mechanism comprises the normally closed
valve 59, FIG. 8, and the linear solenoid (or piezoelectric-based
actuation) mechanism. The configuration and all the components of
the normally closed valve 59 are similar to those used in the
embodiment of FIG. 8. All other components of the Lithium-oxygen
reserve battery embodiment 70 are similar to that of the embodiment
10 of FIG. 3.
[0100] The actuation mechanism of the Lithium-Oxygen reserve
battery embodiment 90 of FIG. 11 comprises a metallic bellow 92,
which can be formed of the same metal with which the battery core
housing 11 is constructed, such as stainless steel. The bellow 92
is fixedly attached to the side surface 93 of the battery core
housing 11, such as by welding or brazing, and the attachment is
tested to ensure that is fully sealed. The bellow 92 is provided
with a sealed cap 94, which may be integral to the bellow 92. A
linear solenoid actuator 95 (or a piezoelectric or the like
electrically actuated device) is positioned inside the bellow and
fixed to the cap 94 as can be seen in FIG. 11. In FIG. 11, the
terminals 101 indicate the powering terminals of the solenoid 95,
which are passed through the electrical insulations (not shown)
provided in the cap 94. The actuating core 96 of the solenoid 95 is
then attached to a conical section shaped mass member 97. The mass
member 97 is fixedly attached and sealed to the bellow 92. The
conical section mass member 97 (56 in FIG. 8) is positioned close
or in contact with the sloped surface 98 (57 in FIG. 8) of the
member 99 (58 in FIG. 8) of the normally closed valve 59 as can
also be seen in FIG. 11. The solenoid 95 is provided with a proper
return spring so that while it is not energized, the mass member 97
is at the position shown in FIG. 11 and does not force the valve 59
to open. The cap 94 may be provided with a small hole to prevent
the air (gas) trapped inside the below 92 from resisting its
extension.
[0101] The Li-Oxygen reserve battery embodiment 90 of FIG. 11
operates as follows. In normal conditions, the valve 59 is in its
closed state and prevents oxygen gas from entering the porous
carbon-based O.sub.2 cathode of the battery core. In this state,
the biasing forces of the compressively preloaded spring 102 (65 in
FIG. 8) and the pressure of the oxygen gas ensures that the valve
59 stays closed. The Li-Oxygen reserve battery 90 is therefore in
its inactive state and provides a long shelf life that can
significantly exceed the military required 20 years. If the device
to which the reserve battery 90 is attached is accelerated in the
direction of the arrow 104, the acceleration would act on the
inertia of the mass member 97 and the solenoid core 96, generating
a downward dynamic force as seen in the view of FIG. 11. The
biasing spring in the solenoid 96 (not shown) is preloaded such
that when the acceleration in the direction of the arrow 104 has
reached a prescribed threshold, then the generated dynamic force
would overcome the spring preload and the assembly of the mass
member 97 and the solenoid core 96 would begin to move down as
viewed in FIG. 11. It is appreciated that a preloaded tensile
spring (not shown) may instead be provided around the solenoid core
96 (similar to preloaded tensile spring 86 in FIG. 10) to perform
the same function. If the acceleration in the direction of the
arrow 104 is long enough in duration, the bellow 92 begins to
deform, allowing the conical mass member 97 to move down, thereby
engaging the sloped surface 98 of the member 99 (58 in FIG. 8) and
forcing it to begin to move to the right as seen in the view of
FIG. 11. As a result, the cap 106 (61 in FIG. 8) is lifted from
over the elastomeric gasket 103 (63 in FIG. 8), thereby allowing
the oxygen gas to begin to flow into the porous carbon-based
O.sub.2 cathode section of the battery core and activate the
reserve battery. Then once the acceleration in the direction of the
arrow 104 has ceased, the mass member 97 is forced to return to its
pre-acceleration position shown in FIG. 11 by the preloaded biasing
spring of the solenoid 95, the extended bellow 92, preloaded
compressive spring 102 and the oxygen gas pressure, thereby closing
the valve 59 and stopping the flow of oxygen gas into the battery
core.
[0102] If the applied acceleration in the direction of the arrow
104 is below the prescribed threshold, for example due to
accidental drop of the object to which the reserve battery 90 is
attached, the preloading level of the aforementioned biasing
tensile springs are not overcome, and the mass member 97 assembly
dose not engage the sloped surface 98 of the member 99 and the
valve 59 stays closed.
[0103] It is appreciated by those skilled in the art that the
linear solenoid actuator 95 (or other similar linear or rotary
actuators) may be of a latching type. In such a case, at any point
in time following initial inertial activation, the battery may be
activated and made to remain activated without requiring power to
be continuously be applied to the actuator 95. The solenoid may
also be actuated less than the distance that activates the latching
mechanism, thereby providing the capability to reactivate the
reserve battery several times until it is desired to stay
permanently activated, at which time the solenoid is actuated to
the point of activating its latching mechanism.
[0104] It is also appreciated by those skilled in the art that all
electronic and drive components and the capacitor 107 that are used
to sense the reserve battery embodiment 90 power level and activate
the battery as needed may also be integrated inside the reserve
battery housing 11. Such self-contained Li-Oxygen reserve batteries
would greatly simplify their integration into various devices such
as gun-fired munitions.
[0105] In the Li-Oxygen reserve battery embodiment 90, the inertial
activation in response to the prescribed acceleration profile is
configured to allow enough oxygen gas into the battery core to
power the device electronics and power control system and to
operate the solenoid 95 to open and close the valve 59 when needed
to supply the required electrical energy. The reserve battery
embodiment 90 may also be provided with a capacitor or
super-capacitor 107 as was shown in FIG. 10 to form a
"Lithium-Oxygen hybrid reserve battery".
[0106] In the Lithium-Oxygen reserve battery embodiment 90 of FIG.
11, similar to the embodiment 70 of FIG. 10, the inertial
activation in response to a prescribed acceleration profile is
configured to allow enough oxygen gas into the battery core to
power the device electronics and power control system and to
operate the on/off activation actuation device, in this case the
solenoid 95. Alternatively, the Lithium-Oxygen reserve battery
embodiment 90 may be paired with a capacitor (or supercapacitor)
107, which is charged by the electrical energy generated by the
initial activation of the reserve battery. The electrical energy
stored in the capacitor 107 can then be used by the object to which
the reserve battery is attached (e.g., a gun fired munition), and
to re-activate the reserve battery as needed by the actuator 95.
Such a combined Lithium-Oxygen reserve battery and capacitor
(super-capacitor) reserve power source forms a previously described
"Lithium-Oxygen hybrid reserve battery".
[0107] It is appreciated by those skilled in the art that such
"Lithium-Oxygen hybrid reserve batteries" are particularly
advantageous for use in applications in which they are required to
provide low power for long periods of times and only occasionally
have to provide high power, usually for relatively short periods of
time. In such applications, the reserve battery only needs to be
activated for very short periods of times to charge the capacitor
and have the capacitor supply the low power to usually low power
electronics for hours and sometimes for days until either high
power is required to be provided or when the capacitor power is low
and it needs to be recharged, at which time the capacitor supplies
power to the activation actuator, FIGS. 10 and 11.
[0108] In one embodiment of the present "Lithium-Oxygen hybrid
reserve batteries", a controller/processor, such as an electronic
control circuit 107a can be provided to detect the voltage level of
the hybrid reserve battery electrical energy storage capacitor
(e.g., 91 in FIG. 10) and energize the battery activation actuator
(80 in FIG. 10) for a prescribed amount of time to allow a
prescribed amount of oxygen gas to flow into the battery core for
its activation. In addition, the electronic control circuit may be
provided with a microprocessor 107b and memory 107c so that it
could be programmed to provide a prescribed power level based on a
received sensory input and/or planned profile. The control circuit
electrically connecting the capacitor (energy storage device) to
the terminals 101 of the solenoid 95 (actuation device).
[0109] It is also appreciated by those skilled in the art that the
Lithium-Oxygen reserve battery embodiment 90 may also be activated
directly by energizing the solenoid 95 in non-shock loading
activation applications.
[0110] The Lithium-oxygen reserve battery embodiment 90 of FIG. 11
is configured to be activated either during the munitions firing
for a short period of time and then by the integrated actuation
device or directly by the integrated actuation device, in this case
the linear solenoid 95. The Lithium-oxygen reserve battery
embodiment 90 may also be constructed without the electrical
actuator as shown in the schematic of FIG. 12 (indicated as the
embodiment 100) and instead be provided with at least a pair of
bosses 108 with (interior or exterior) threads 109 on the outside
surface of the battery housing or those 110 with internal threads,
for the used to attach the desired actuation device (linear or
screw type rotary electrical or piezoelectric-based linear actuator
or the like). In both options, the bosses are fixedly attached to
the battery housing surface, such as by welding or brazing or the
like and fully sealed to keep the battery core hermetically sealed
for long shelf life. The Lithium-oxygen reserve battery embodiment
100 operates as was previously described for the reserve battery
embodiment 90 of FIG. 11.
[0111] In the schematic of FIG. 13A, the blow-up view "B", FIG. 12,
showing the valve 59 and the actuating conical mass section 97 and
the bellow 92 is redrawn. In an alternative configuration, the
valve 59 may be replaced with the configuration shown in the
embodiment 60 of FIG. 9. With the replaced valve, the blow-up view
"B" would then become as shown in FIG. 13B.
[0112] Then in the normal conditions, as was described for the
embodiment of FIG. 9, the preloaded compressive spring 115 and the
pressurized oxygen gas in the container 18 keep the valve closed
and prevent oxygen gas from entering the porous carbon-based
O.sub.2 cathode of the battery core, FIG. 12. Then if the device to
which the reserve battery 100 is attached is accelerated in the
direction of the arrow 112, the acceleration would act on the
inertia of the mass member 97, generating a downward dynamic force.
The compressive spring 115 is preloaded such that when the
acceleration in the direction of the arrow 112 has reached a
prescribed threshold, then the generated dynamic force would
overcome the spring preload and the mass member 97 begin to move
downward as viewed in FIG. 12. Here, the spring rate of the metal
bellow is considered to be negligible, otherwise it must also be
considered. If the acceleration in the direction of the arrow 112
is long enough in duration, the cap 116 is moved to the right
enough to allow the pressurized oxygen gas to begin to flow into
the porous carbon-based O.sub.2 cathode section of the battery core
and activate the reserve battery. Once the cap 116 has moved to the
right, the gap between the bottom surface of the cap 116 and the
surface 119 of the container 18 is configured to be enough to allow
the "locking" member 121 to be pushed under the cap 116 and prevent
the cap to close the flow of the oxygen gas into the battery core
once the acceleration in the direction of the arrow 112 has ceased.
Thereby, the reserve battery is activated and stays activated after
the acceleration event, for example due to the firing of a munition
in which the reserve battery is mounted. If the applied
acceleration in the direction of the arrow 112 is below the
prescribed threshold, for example due to accidental drop of the
object to which the reserve battery 100 is attached, the valve
stays closed and the reserve battery is not activated.
[0113] In an alternative configuration of FIG. 13B, once the valve
(59 in FIG. 12) is opened due to the prescribed acceleration event,
the valve stays open and the reserve battery 100 stays activated
from then on. On the other hand, the valve configuration shown in
FIG. 12 and its blow-up view of FIG. 13A provides a reserve battery
that requires activation of its electrical actuation device (e.g.,
a linear electrical solenoid) to open the valve 59 to reactivate
the reserve battery after its initial inertial (or direct solenoid
operated electrical) activation. In this embodiment, to keep the
battery permanently activated after cycles of
activation/deactivation, the actuation mechanism needs to be kept
energized. To avoid the waste of electrical energy to keep the
actuation device energized, the modification shown in the blow-up
schematic of FIG. 13C is made to the activation mechanism of the
reserve battery.
[0114] In the activation mechanism of FIG. 13C, the same valve 59
of the embodiment 100 of FIG. 12 is used. The conical section mass
member 120 (97 in FIG. 13B) is similarly fixedly attached to the
bellow 123 (92 in FIG. 13B). The conical section mass member 120 is
also positioned close or in contact with the sloped surface 124 of
the member 125 (113 in FIG. 13B) of the normally closed valve 59 as
can also be seen in FIG. 13B. The actuation mechanism that is
provided for the reserve battery activation (for example, the
linear solenoid 95 of FIG. 11 or other linear or rotary electrical
actuator or the like) is provided with a proper return spring so
that while it is not energized, the mass member 120 is at the
position shown in FIG. 13C and does not force the valve 59 to
open.
[0115] The mass member 120 is also provided with a link member 127,
which is attached to the mass member 120 by a pin joint 128. The
link member 127 is provided by a preloaded compressive spring 129,
which is attached to the mass member 129 by the pin joint 131 and
is biased to rotate the link member 127 in the clockwise direction
as viewed in FIG. 13C and mostly rest against the surface 124 of
the member 125.
[0116] Then in the normal conditions, as was described for the
embodiment of FIG. 9, the preloaded compressive spring 115 (FIG.
13B) and the pressurized oxygen gas in the container 18 keep the
valve closed and prevent oxygen gas from entering the porous
carbon-based O.sub.2 cathode of the battery core, FIG. 12. Then if
the device to which the reserve battery 100 is attached is
accelerated in the direction of the arrow 112, the acceleration
would act on the inertia of the mass member 120, FIG. 13C,
generating a downward dynamic force. The compressive spring (115 in
FIG. 13b) of the valve 59 is preloaded such that when the
acceleration in the direction of the arrow 112 has reached a
prescribed threshold, then the generated dynamic force would
overcome the spring preload and the mass member 120 begins to move
downward as viewed in FIG. 13C. Here, the spring rate of the metal
bellow is considered to be negligible, otherwise it must also be
considered. If the acceleration in the direction of the arrow 112
is long enough in duration, the cap 126 is moved to the right,
allowing the pressurized oxygen gas to begin to flow into the
porous carbon-based O.sub.2 cathode section of the battery core and
activate the reserve battery. It is noted that the actuation device
of FIG. 13C is configured such that the above prescribed
acceleration profiles would not move the mass member 120 down
enough along the surface 124 to have the tip 132 of the link member
127 to pass the tip 133 of the member 125 as can be seen in FIG.
13C.
[0117] The Lithium-oxygen reserve battery embodiment 100 of FIG. 12
is configured to be activated either during the munitions firing
for a short period of time and then by the integrated actuation
device (such as the linear actuator 95 as shown in FIG. 11) or
directly by the integrated actuation device 95. The Lithium-oxygen
reserve battery embodiment 100 may then be activated and
deactivated on command by the indicated integrated actuation
device. However, during each activation process, the integrated
actuation device of FIG. 13C advances the mass member 120 down
along the surface 124 such that the tip 132 of the link member 127
would not pass the tip 133 of the member 125, so that the
integrated actuation device could be commanded to bring the mass
member 120 back to its position shown in FIG. 13C, thereby closing
the flow of oxygen gas into the battery core and reverting the
battery to its reserve state.
[0118] However, at any moment, the integrated actuation device can
be used to displace the mass member down enough so that the tip 132
of the link member 127 would clear the tip 133 of the member 125,
thereby the link member 127 would rotate in the clockwise direction
until it is stopped by the stop member 135 of the mass member 120.
As a result, once the integrated actuation device is de-energized,
the link 132 engages the lower surface 136 of the member 125 and
prevents the mass member 120 from returning to its position shown
in FIG. 13C. In the meanwhile, the opened valve 59 would stay open
and the oxygen gas would continue flowing into the reserve battery
core.
[0119] The Lithium-oxygen reserve battery embodiment 10 of FIG. 3
was shown to be configured to activate when subjected to a
prescribed acceleration profile in the direction of the arrow 22.
The reserve battery embodiment 10 may, however, be modified so that
it could be activated by electrical initiation of a pyrotechnic
charge, i.e., using an electrical initiator. Such a Lithium-oxygen
reserve battery embodiment 130 is shown in the cross-sectional
schematic of FIG. 14.
[0120] In the Lithium-oxygen reserve battery embodiment 130 of FIG.
14, the activation mechanism comprises a metallic bellow 137 that
is fixedly attached to the surface 21 of the pressurized oxygen
container 18, such as by welding or brazing. An end member 138 is
also attached to the other end of the bellow, such as by welding or
brazing. The attachments of the bellow to the surface 21 and the
end member 138 must be sealed and the bellow 137 and end member 138
can be formed from the same material as the container 18, such as
stainless steel. An electrically initiated gas generating
pyrotechnic device 141 is provided inside the sealed bellow 137.
Initiator service wires 141 are indicated by the numeral 142 in
FIG. 14.
[0121] The common wall 19 between the container 18 and the battery
core (inside housing 11) is provided with a relatively small
opening 14 into the battery core, which is normally sealed by a
metallic diaphragm 13. In general, the housings 11 and 18 are made
with stainless steel and the diaphragm 13 is also a thin stainless
sheet that is welded to the wall 19. The end member 138 is provided
with a sharp cutting member 139, which is positioned above the hole
14.
[0122] The Li-Oxygen reserve battery embodiment 130 operates as
follows. In normal conditions, the diaphragm 13 prevents oxygen gas
from entering the porous carbon-based O.sub.2 cathode of the
battery core. Then if the electrical gas generating pyrotechnic
device 141 is initiated, the pressure due to the generated gas
would extend the bellow 137, thereby causing the end member 138 to
move down and for the sharp cutting member 139 to reach and rupture
the diaphragm 13, thereby allowing the oxygen gas to begin to flow
into the porous carbon-based O.sub.2 cathode section of the battery
core and activate the reserve battery.
[0123] It is appreciated by those skilled in the art that the
activation mechanisms such as the externally actuated manual or
powered actuation activation mechanisms of the embodiments of FIGS.
5, 6, 7, 10, 11 and 12 may be configured with other types of
mechanisms and powered actuators but to perform the same intended
functions. The mechanisms and their actuation devices shown and
described are primarily intended to describe the basic methods of
activating the present Lithium-Oxygen reserve batteries and
examples of mechanisms that can be used to activate them for
continuous use or for multiple activation/deactivation. For
example, the activation mechanism of the embodiment 50 of FIG. 7
may be readily modified for manual operation as shown in the
embodiment 150 of FIG. 15 or by externally powered actuation
devices as described below.
[0124] In the Li-Oxygen reserve battery embodiment 150 of FIG. 15,
the valve assembly 59, FIG. 7, is still used and may be positioned
more centrally as shown in FIG. 15. However, since its sloped
section 57 is no longer needed, it is eliminated as can be seen in
the schematic of FIG. 15. The bellow-based actuation mechanism of
the embodiment 50 of FIG. 7 is then modified and repositioned as
follows. The mechanism bellow 155 is similarly attached to the
outer surface of the oxygen container 18, such as by welding or
brazing. The bellow 155 is then provided with a cap 156, which
seals the bellow 155 and is attached to it, such as by welding or
brazing. The guide 153 is similarly attached to the interior
surface of the container 18 against the bellow 155. A pin 151 is
provided as shown in FIG. 15, which can freely slide in the guide
153 and is fixedly attached to the cap 156 on one end and to the
valve assembly 59 cap 154 on the other end. A ring or the like
member 152 is also fixedly attached to the cap 156 for manual
activation of the reserve battery.
[0125] The Li-Oxygen reserve battery embodiment 150 of FIG. 15
operates as follows. In normal conditions, the valve 59 is closed
and prevents oxygen gas from entering the porous carbon-based
O.sub.2 cathode of the battery core. The reserve battery 150 is
therefore in its inactive state and provides a long shelf life that
can significantly exceed the military required 20 years. The user
may then manually pull the ring 152, thereby pulling the pin 151 up
and lifting the cap 154 from over the elastomeric sealing gasket
(63 in FIG. 7), thereby allowing the oxygen gas to begin to flow
into the porous carbon-based O.sub.2 cathode section of the battery
core and activate the reserve battery. Then when the user releases
the ring 152, the extended bellow 155 would tend to spring back and
assisted with the compressed oxygen gas pressure acting on the cap
154 would close the valve 59 and stop transfer of pressurized gas
into porous carbon-based O.sub.2 cathode section of the battery
core. The battery is thereby reverted to its reserve state and the
battery core would stop generating electrical energy once its
present oxygen gas has been consumed.
[0126] It is appreciated by those skilled in the art that the cap
156 of the bellow 155, FIG. 15, may also be displaced up and down,
as viewed in FIG. 15, by an externally positioned linear or rotary
electrical or piezoelectric-based or pneumatic or the like
actuation device as was described, for example, for the embodiment
70 of FIG. 10, on commands provided by the system controls as is
well known in the art.
[0127] The Lithium-Oxygen reserve battery embodiments 10 and 20 of
FIGS. 3 and 4, respectively, are configured to be activated when
the device to which they are attached is subjected to a prescribed
acceleration profile, such as firing of a gun. In many munition
applications, such as in rockets, the reserve battery is required
to be activated at prescribed accelerations that are low in
magnitude, for example in tens of Gs rather than thousands in the
case of gun-fired munitions, and lasts a few tens of milliseconds.
In such applications, the activation mechanisms of the embodiments
10 and 20 of FIGS. 3 and 4, respectively, may not be suitable since
they may require very large inertial mass (16 and 27 in FIGS. 3 and
4, respectively) to make them capable of rupturing the provided
diaphragms to activate the reserve battery. The activation
mechanism of the Lithium-Oxygen reserve battery embodiment 160 of
FIG. 16 is configured for such relatively low G prescribed firing
accelerations or the like applications.
[0128] In the schematic of FIG. 16, all other components of the
reserve battery are similar to that of the embodiment 10 of FIG. 3,
except for its inertial activation mechanism. As can be seen in
FIG. 16, the Lithium-Oxygen reserve battery embodiment 160 is
provided with an activation mechanism that comprises a link 161,
which is attached to the surface 163 of the pressurized oxygen
container by the rotary joint 162. In normal conditions the link
161 is in the configuration shown in FIG. 16, in which the tip 174
of the link rests on provided "step" on the tip 171 of the inertial
mass 170. In this configuration, the inertial mass 170 is being
pushed against the tip 174 of the link 161 by the preloaded
compressive spring 173. The preloaded compressive spring 173 is
positioned between the inertial mass 170 and the support 172, which
is fixedly attached to the surface 163 of the pressurized oxygen
container. The link 161 is also held in its position shown in FIG.
16 by the preloaded compressive spring 167, which is attached to
the link 161 by the pin joint 168 on one end and to the inside of
the pressurized oxygen container by the pin joint 169 on the other
end. The link 161 is also provided with a sharp cutting member 164,
which in the normal condition of FIG. 16 is positioned above the
hole 165 in the side 163 of the pressurized oxygen container that
is covered by the diaphragm 166, which can be metallic and attached
to the container surface by welding or brazing.
[0129] The Li-Oxygen reserve battery embodiment 160 of FIG. 16
operates as follows. In normal conditions, the diaphragm 166
prevents oxygen gas from entering the porous carbon-based O.sub.2
cathode of the battery core. If the device to which the reserve
battery 160 is attached is accelerated in the direction of the
arrow 175, the acceleration would act on the inertial mass 170,
generating a downward dynamic force. The compressive spring 173 is
preloaded such that when the acceleration in the direction of the
arrow 175 has reached a prescribed threshold, then the generated
dynamic force would overcome the spring preload and the inertial
mass 170 would begin to move downward as viewed in FIG. 16. If the
acceleration in the direction of the arrow 175 is long enough in
duration, the inertial mass 170 moves down enough so that the tip
171 clears the tip 174 of the link 161. The preloaded compressive
spring 167 will then accelerate the link 161 in rotation in the
clockwise direction until the sharp cutting member 164 strikes the
diaphragm 166 and causes it to rupture, thereby allowing the oxygen
gas to begin to flow into the porous carbon-based O.sub.2 cathode
section of the battery core and activate the reserve battery. If
the duration of the applied acceleration in the direction of the
arrow 175 is very short, for example due to accidental drop of the
object to which the reserve battery 160 is attached, the inertial
mass 170 and spring 173 system is configured such that the link 161
is not released and thereby the reserve battery is not
activated.
[0130] In various embodiments disclosed above, for any components
described as being movable within the porous carbon-based O.sub.2
cathode, the porous carbon-based O.sub.2 cathode is configured to
permit such movement, such as having a corresponding void.
[0131] While there has been shown and described what is considered
to be preferred embodiments of the invention, it will, of course,
be understood that various modifications and changes in form or
detail could readily be made without departing from the spirit of
the invention. It is therefore intended that the invention be not
limited to the exact forms described and illustrated, but should be
constructed to cover all modifications that may fall within the
scope of the appended claims.
* * * * *